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International Journal of Molecular... Aug 2021The aim of this study was to evaluate the effect of different concentrations of chitosan polymer on dentinal enzymatic activity by means of gelatin and in situ...
The aim of this study was to evaluate the effect of different concentrations of chitosan polymer on dentinal enzymatic activity by means of gelatin and in situ zymography. Human dentin was frozen and ground in a miller. Dentin powder aliquots were demineralized with phosphoric acid and treated with three different concentrations of lyophilized chitosan polymer (1, 0.5 and 0.1 wt%) dissolved in distilled water. Dentin proteins were extracted from each experimental group and electrophoresed under non-reducing conditions in 10% SDS-PAGE containing fluorescein-labeled gelatin. After 48 h in the incubation buffer at 37 °C, proteolytic activity was registered under long-wave UV light scanner and quantified by using Image J software. Furthermore, additional teeth ( = 4) were prepared for the in situ zymographic analysis in unrestored as well as restored dentin pretreated with the same chitosan primers. The registered enzymatic activity was directly proportional to the chitosan concentration and higher in the restored dentin groups ( < 0.05), except for the 0.1% chitosan primer. Chitosan 0.1% only showed faint expression of enzymatic activity compared to 1% and 0.5% concentrations. Chitosan 0.1% dissolved in water can produce significant reduction in MMPs activity and could possibly contribute to bond strength preservation over time.
Topics: Chelating Agents; Chitosan; Dentin; Humans; Materials Testing; Matrix Metalloproteinases
PubMed: 34445554
DOI: 10.3390/ijms22168852 -
International Endodontic Journal Mar 2019A thorough understanding of the biology of the dentine-pulp complex is essential to underpin new treatment approaches and maximize clinical impact for regenerative...
A thorough understanding of the biology of the dentine-pulp complex is essential to underpin new treatment approaches and maximize clinical impact for regenerative endodontics and minimally invasive vital pulp treatment (VPT) strategies. Following traumatic and carious injury to dentine-pulp, a complex interplay between infection, inflammation and the host defence responses will occur, which is critical to tissue outcomes. Diagnostic procedures aim to inform treatment planning; however, these remain clinically subjective and have considerable limitations. As a consequence, significant effort has focussed on identification of diagnostic biomarkers, although these are also problematic due to difficulties in identifying appropriate diagnostic fluid sources and selecting reproducible biomarkers. This is further compounded by the link between inflammation and repair as many of the molecules involved exhibit significant multifunctionality. The tertiary dentine formed in response to dental injury has been purposefully termed reactionary and reparative dentine to enable focus on associated biological processes. Whilst reactionary dentine produced in response to milder injury is generated from surviving primary odontoblasts, reparative dentine, in response to more intense injury, requires the differentiation of new odontoblast-like cells derived from progenitor/stem cells recruited to the injury site. These two diverse processes result in very different outcomes in terms of the tertiary dentine produced and reflect the intensity rather than specific nature (nonexposure versus exposure) of the injury. The subsequent identification of the odontoblast-like cell phenotype remains challenging due to lack of unique molecular or morphological markers. Furthermore, the cells ultimately lining the newly deposited dentine provide only a snapshot of events. The specific source and plasticity of the progenitor cells giving rise to the odontoblast-like cell phenotype are also of significant debate. It is likely that improved characterization of tertiary dentine may better clarify the influence of cell derivation for odontoblast-like cells and their diversity. The field of regenerative endodontics offers exciting new treatment opportunities, and to maximize outcomes, we propose that the term regenerative endodontics should embrace the repair, replacement and regeneration of dentine-pulp.
Topics: Dental Pulp; Dental Pulp Exposure; Dentin; Dentin, Secondary; Humans; Regenerative Endodontics; Wound Healing
PubMed: 30724394
DOI: 10.1111/iej.13064 -
Scientific Reports Feb 2017A novel agarose hydrogel biomimetic mineralization system loaded with calcium and phosphate was used to remineralize dentin and induce the oriented densely parallel...
A novel agarose hydrogel biomimetic mineralization system loaded with calcium and phosphate was used to remineralize dentin and induce the oriented densely parallel packed HA layer on defective dentin surface in vivo in a rabbit model. Firstly, the enamel of the labial surface of rabbits' incisor was removed and the dentin was exposed to oral environment. Secondly, the hydrogel biomimetic mineralization system was applied to the exposed dentin surface by using a custom tray. Finally, the teeth were extracted and evaluated by scanning electron microscopy, X-ray diffraction, and nanoindentation test after a certain time of mineralization intervals. The regenerated tissue on the dentin surface was composed of highly organised HA crystals. Densely packed along the c axis, these newly precipitated HA crystals were perpendicular to the underlying dental surface with a tight bond. The demineralized dentin was remineralized and dentinal tubules were occluded by the grown HA crystals. The nanohardness and elastic modulus of the regenerated tissue were similar to natural dentin. The results indicated a potential clinical use for repairing dentin-exposed related diseases, such as erosion, wear, and dentin hypersensitivity.
Topics: Animals; Biomimetics; Dentin; Elastic Modulus; Hydrogels; Male; Rabbits; Sepharose; Tooth Remineralization
PubMed: 28167823
DOI: 10.1038/srep41955 -
Dental Materials Journal May 2021It is crucial to emphasize the biomineralization therapeutic method to repair etched dentin in clinic. Non-collagenous proteins (NCPs) play critical role in the...
It is crucial to emphasize the biomineralization therapeutic method to repair etched dentin in clinic. Non-collagenous proteins (NCPs) play critical role in the biomineralization of dentine. In this paper, we synthesized the phosphate-terminated polyamidoamine dendrimer (PAMAM-POH) by one-step modification successfully and examined by Fourier-transform infrared spectroscopy (FTIR) and H-nuclear Magnetic Resonance (H-NMR) to characterize the structure of PAMAM-POH. PAMAM-POH and carboxylterminated dendrimers (PAMAM-COOH) were applied as the dual biomimetic analogs of NCPs. Through the characterization of FT-IR, field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD), the surfaces of human dentin were covered with regenerated crystals and the dentinal tubules were occluded by PAMAM-POH and PAMAM-COOH. In summary, the combination of PAMAM-POH and PAMAM-COOH may be another feasible therapeutic method for the treatment of dentin caries and dentin hypersensitivity.
Topics: Biomimetics; Dendrimers; Dentin; Humans; Microscopy, Electron, Scanning; Spectroscopy, Fourier Transform Infrared
PubMed: 33642446
DOI: 10.4012/dmj.2020-222 -
International Journal of Molecular... Mar 2015This study aimed to review the laboratory methods on biomimetic remineralization of demineralized human dentine. A systematic search of the publications in the PubMed,... (Review)
Review
This study aimed to review the laboratory methods on biomimetic remineralization of demineralized human dentine. A systematic search of the publications in the PubMed, TRIP, and Web of Science databases was performed. Titles and abstracts of initially identified publications were screened. Clinical trials, reviews, non-English articles, resin-dentine interface studies, hybrid layer studies, hybrid scaffolds studies, and irrelevant studies were excluded. The remaining papers were retrieved with full texts. Manual screening was conducted on the bibliographies of remaining papers to identify relevant articles. A total of 716 studies were found, and 690 were excluded after initial screening. Two articles were identified from the bibliographies of the remaining papers. After retrieving the full text, 23 were included in this systematic review. Sixteen studies used analogues to mimic the functions of non-collagenous proteins in biomineralization of dentine, and four studies used bioactive materials to induce apatite formation on demineralized dentine surface. One study used zinc as a bioactive element, one study used polydopamine, and another study constructed an agarose hydrogel system for biomimetic mineralization of dentine. Many studies reported success in biomimetic mineralization of dentine, including the use of non-collagenous protein analogues, bioactive materials, or elements and agarose hydrogel system.
Topics: Acrylic Resins; Biocompatible Materials; Biomimetic Materials; Biomimetics; Calcium Phosphates; Dental Cements; Dentin; Humans; Tooth Remineralization
PubMed: 25739078
DOI: 10.3390/ijms16034615 -
Dental Materials : Official Publication... Apr 2018Eight repetitive nucleotide sequences of aspartate-serine-serine (8DSS) derived from dentin phosphoprotein (DPP) has been proved to be a good remineralization agency. In...
OBJECTIVE
Eight repetitive nucleotide sequences of aspartate-serine-serine (8DSS) derived from dentin phosphoprotein (DPP) has been proved to be a good remineralization agency. In this study, 8DSS peptide was employed to induce dentinal tubule occlusion.
METHODS
Dentin samples were acid-etched, and then the samples were coated with 8DSS solution. The binding capacity of 8DSS to acid-etched dentin was tested by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Subsequently, the 8DSS-treated dentin samples were immersed in artificial saliva for 1, 2 and 4 weeks. After 4 weeks, the remineralized dentin was treated with 6wt% citric acid (pH 1.5) solution for 1min. Dentin permeability measurement and scanning electron microscopy (SEM) were carried out after different periods. Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used to identify the mineral phase of the regenerated minerals.
RESULTS
The results showed that 8DSS had a good binding capacity to the acid-etched dentin, and significantly reduced the dentin permeability by inducing minerals deposited within the dentinal tubules. After 4 weeks, all the dentinal tubules were occluded by large bulk of regenerated minerals, which largely decreased the diameters of the tubules. The regenerated minerals deposited with a deep depth within the dentinal tubules, ensuring an effective occlusion even after an acid challenge. The results of XRD and EDS confirmed that the regenerated minerals were mainly hydroxyapatite (HA).
SIGNIFICANCE
8DSS peptide induced strong dentinal tubule occlusion. 8DSS have a great potential to be used in the treatment of dentin hypersensitivity in the future.
Topics: Acid Etching, Dental; Dentin; In Vitro Techniques; Materials Testing; Microscopy, Electron, Scanning; Peptides; Saliva, Artificial; Spectroscopy, Fourier Transform Infrared; Surface Properties; X-Ray Diffraction
PubMed: 29395469
DOI: 10.1016/j.dental.2018.01.006 -
Journal of Comparative Pathology May 2021Histopathological changes in tooth structures in dogs with calculus have not been described. The aim of this study was to evaluate the frequency of various...
Histopathological changes in tooth structures in dogs with calculus have not been described. The aim of this study was to evaluate the frequency of various histopathological changes in the dentine of teeth that had been surgically extracted from dogs with calculus. Data including breed, sex, age, reason for tooth extraction and dental history were obtained for each animal. A total of 158 teeth (45 incisors, 31 canines, 35 premolars and 47 molars) with calculus were extracted from 74 dogs of various ages and breeds. The teeth were decalcified, processed in paraffin wax and stained with haematoxylin and eosin for histopathological analysis. Of the 158 analysed teeth, 71 had dentinal changes, including 45 with external resorption cavities, 11 with osteodentine, six with internal resorption cavities, four with tertiary dentine, four with dentinal degeneration or fragmentation, and one with predentine degeneration or fragmentation. Canine teeth were the least commonly affected. Areas of dentinal degeneration or fragmentation unrelated to resorption cavities were only seen in the incisor and molar teeth. Dentinal changes and their frequencies were similar among the incisor, premolar and molar teeth. The presence or extension of dental calculus was not associated with the type or frequency of dentinal changes.
Topics: Animals; Dental Calculus; Dentin; Dog Diseases; Dogs; Tooth
PubMed: 34119235
DOI: 10.1016/j.jcpa.2021.03.004 -
Nanoscale Dec 2022Dentin hypersensitivity (DH) treatment is far from being unequivocal in providing a superior strategy that combines immediate and long-term efficiency of dentinal tubule...
Dentin hypersensitivity (DH) treatment is far from being unequivocal in providing a superior strategy that combines immediate and long-term efficiency of dentinal tubule (DT) occlusion and clinical applicability. In order to achieve this aim, a type of multifunctional yolk-shell nanocomposite with acid resistance, mechanical resistance and biomineralization properties was developed in this study, which consists of a silica/mesoporous titanium-zirconium nanocarrier (STZ) and poly(allylamine hydrochloride) (PAH)-stabilized amorphous calcium phosphate (ACP) liquid precursor. First, the nanocomposite, named as PSTZ, immediately occluded DTs and demonstrated outstanding acid and mechanical resistance. Second, the PSTZ nanocomposite induced intrafibrillar mineralization of single-layer collagen fibrils and remineralization of demineralized dentin matrix. Finally, PSTZ promoted the odontogenic differentiation of dental pulp stem cells by releasing ACP and silicon ions. The reconstruction of the dentin-mimicking hierarchical structure and the introduction of newly formed minerals in the upper, middle and lower segments of DTs, defined as sandwich-like structures, markedly reduced the permeability and achieved superior long-term sealing effects. The nanocomposite material based on mesoporous yolk-shell carriers and liquid-phase mineralized precursors developed in this study represents a versatile biomimetic sandwich desensitization strategy and offers fresh insight into the clinical management of DH.
Topics: Dentin; Collagen; Silicon Dioxide; Nanocomposites
PubMed: 36408803
DOI: 10.1039/d2nr04993g -
Oral Diseases Apr 2018To explore the mineral features of dentin and cementum in hypoplastic Amelogenesis imperfecta AI teeth.
OBJECTIVE
To explore the mineral features of dentin and cementum in hypoplastic Amelogenesis imperfecta AI teeth.
MATERIALS AND METHODS
Forty-four (44) teeth cleaned and free of caries were used: 20 control and 24 affected by hypoplastic amelogenesis imperfecta. Thirty-two teeth were studied by pQCT, cut in sections, and analyzed under microradiography, polarized light microscopy, and confocal Raman spectroscopy. Eight teeth were observed under scanning electron microscope. Four teeth were used for an X-ray diffraction. The mineral density data were analyzed statistically with the Mann-Whitney U test, using GraphPad InStat software.
RESULTS
Both coronal dentin and radicular dentin were less mineralized in AI teeth when compared to control (respectively 6.2% and 6.8%; p < .001). Root dentinal walls were thin and irregular, while the cellular cementum layers were thick, reaching sometimes the cervical region of the tooth. Regular dentinal tubules and sclerotic dentin areas were noticed. Partially tubular or cellular dysplastic dentin and hyper-, normo-, or hypomineralized areas were noticed in the inter-radicular areas of hypoplastic AI teeth. The main mineral component was carbonate hydroxyapatite as explored by Raman spectroscopy and X-ray diffraction.
CONCLUSIONS
Dentin and cementum in hypoplastic AI teeth are (i) hypomineralized, (ii) constituted of carbonate hydroxyapatite, and (iii) of non-homogenous structure.
Topics: Adolescent; Adult; Amelogenesis Imperfecta; Dental Cementum; Dentin; Humans; Microradiography; Microscopy, Electron, Scanning; Microscopy, Polarization; Minerals; Spectrum Analysis, Raman; Tomography, X-Ray Computed; Tooth; X-Ray Diffraction; Young Adult
PubMed: 28771955
DOI: 10.1111/odi.12724 -
Journal of Dentistry Aug 2014To evaluate, in vitro, the effects of ionizing radiation on the mechanical and micro-morphological properties of enamel and dentin of permanent teeth. (Comparative Study)
Comparative Study
OBJECTIVES
To evaluate, in vitro, the effects of ionizing radiation on the mechanical and micro-morphological properties of enamel and dentin of permanent teeth.
METHODS
Enamel and dentin microhardness (n=12 hemi-sections) was evaluated at three depths (superficial, middle and deep) prior to (control) and after every 10Gy radiation dose up to a cumulative dose of 60Gy by means of longitudinal microhardness. Data were analyzed using two-way analysis of variance and Tukey's test at a significance level of 5%. Enamel and dentin morphology was assessed by scanning electron microscopy (SEM) for semi-quantitative analysis (n=8 hemi-sections). Data were analyzed using Kruskal-Wallis and Dunn's or Fisher exact tests at a significance level of 5%.
RESULTS
The application of ionizing radiation did not change the overall enamel microhardness, although an increase in superficial enamel microhardness was observed. The micro-morphological analysis of enamel revealed that irradiation did not influence rod structure but interprismatic structure became more evident. Dentin microhardness decreased after 10, 20, 30, 50 and 60Gy cumulative doses (p<0.05) compared with non-irradiated dentin, mainly in the middle portion of the tissue. The micro-morphological analysis revealed fissures in the dentin structure, obliterated dentinal tubules and fragmentation of collagen fibers after 30 and 60Gy cumulative doses.
CONCLUSIONS
Although ionizing radiation did not affect the enamel microhardness of permanent teeth as a whole, an increase in superficial enamel microhardness was observed. Dentin microhardness decreased after almost all radiation doses compared with the control, with the greatest reduction of microhardness in the middle depth region. The morphological alterations on enamel and dentin structures increased with the increase of the radiation dose, with a more evident interprismatic portion, presence of fissures and obliterated dentinal tubules, and progressive fragmentation of the collagen fibers.
CLINICAL SIGNIFICANCE
This study shows that irradiation affects microhardness and micro-morphology of enamel and dentin of permanent teeth. The effects of gamma irradiation on dental substrate might contribute to increased risk of radiation tooth decay associated with salivary changes, microbiota shift and high soft and carbohydrate-rich food intake.
Topics: Cobalt Radioisotopes; Collagen; Dental Enamel; Dentin; Dose Fractionation, Radiation; Hardness; Humans; In Vitro Techniques; Microscopy, Electron, Scanning; Molar; Radiotherapy Dosage; Radiotherapy, High-Energy
PubMed: 24887361
DOI: 10.1016/j.jdent.2014.05.011